Generally, neutral density color wheel filters are used to provide more bits for data processing within a color segment time of the color wheel. Typically, a lower density color segment is included in the color wheel to extend the time required to process the least significant bit of a corresponding data sample. One such color wheel design is described by Hewlett et al. U.S. Pat. No. 5,812,303, disclosure of which is incorporated herein by reference in its entirety for all purposes. Typically, the neutral density color wheels are designed using a dielectric coating (e.g., Magnesium, Fluoride, and Aluminum) on the color wheel. The transmissivity of the dielectric coating is adjusted according to a given application.
When light from a light source is incident upon conventional color wheel along an optical path, the dielectric coating of the color wheel partially reflects the incident light back into the optical path. The reflected light is then recycled back from the light source and incidents upon the color wheel for the second time. This recycling of light between the color wheel and the light source increases the effective light transmission through the color wheel filter and detrimentally affects the color properties of a display system. The light transmission through the color wheel becomes dependent upon the system optics and the effective light transmission of the system cannot be accurately determined.